This invention relates generally to a valve means for application within a flow line, more particularly to a reinforced pivotal butterfly valve for industrial application which incorporates bushings to enhance the useful life of the movable parts such as the valve stem. The assembly employs a unique shape-retention mechanism so that the internal resilient seat maintains its shape and resiliency upon assembly and disassembly. The invention includes a unique bolt retention mechanism for locking the stem bolts to the disc valve to prevent the bolts from loosening and backing out thereby causing valve failure. The bolt retention component also serves to keep the bolt from cutting into the "O"-ring seals and thereby prevents seal damage and leaking around the bolt.
Butterfly or disc valves are frequently used in fluid flow lines where it is desired to load or unload fluid materials for shipment or storage. Such uses include tank trailers for transporting fluids (liquid or granular material) from one location to another, as well as fluid flow lines for loading and unloading barges, ships or other means of transportation and storage. Other uses include blowers, dust collectors, and other such devices using flow lines where some control is required.
Butterfly or disc valves are well-known to the art. U.S. Pat. No. 2,740,423 to Stillwagon discloses a disc valve, particularly, a butterfly or valve, designed for use in the low pressure ranges up to approximately 150 p.s.i. or higher. U.S. Pat. No. 2,912,218 to Stillwagon discloses a butterfly valve having a resilient valve seat which seals between two parts of the valve body. U.S. Pat. No. 2,936,778 to Stillwagon shows a butterfly valve for use in a flow line and having a valve that is quickly and easily removable from the assembly for cleaning and repairing.
U.S. Pat. No. 2,994,342 to Stillwagon describes a improvement to the valve shown in his U.S. Pat. No. 2,740,423. U.S. Pat. No. 3,024,802 to Stillwagon also describes a valve and more particularly a butterfly valve and is also improvement of the valves shown in his U.S. Pat. No. 2,912,218.
U.S. Pat. No. 3,043,557 to Stillwagon relates to improvements in butterfly or disc valves and more particularly to improvements in the seating and sealing mechanism between the disc and a resilient seat. U.S. Pat. No. 3,051,435 to Ramsey describes an improvement in butterfly or disc valves adapted for use in pressure ranges up to approximately 150 p.s.i. and even higher.
U.S. Pat. No. 3,024,802 to Stillwagon describes an improvement in his prior disc valve inventions.
U.S. Pat. No. 3,314,641 to Overbaugh describes a butterfly valve with an improved resilient seat member having a rigid reinforcement therein. U.S. Pat. No. 3,127,904 to Stillwagon describes an improvement in butterfly or disc valves used in food processing and the manufacturing of explosives.
U.S. Pat. No. 3,129,920 to Stillwagon describes improvements in conduit connections and more particularly in such connections having disc or butterfly valves therein.
U.S. Pat. No. 3,241,806 to Snell describes a disc valve having a plastic layer or resilient seating surface. U.S. Pat. No. 3,253,815 to Stillwagon describes improved disc valves and disc valve seats adapted for installation between "slip-on" flanges in the pipe line where the flanges extend beyond the ends of the pipes to which they are connected. U.S. Pat. No. 3,233,861 to Stillwagon describes a butterfly valve having a reinforced seat structure.
U.S. Pat. No. 3,306,316 to Stillwagon describes a disc valve and fitting adapted to be connected in a pipe line or system and occupy a space greater than that occupied normally by a disc valve, such as the space normally occupied by a gate or plug valve without the necessity of using extra fittings or adapters to take up the excess space.
U.S. Pat. No. 3,376,015 to Foresman discloses a high pressure butterfly valve. U.S. Pat. No. 3,452,961 to Foresman describes a valve operator for rotating a disc valve through 90 degrees from a closed position to a fully opened position. U.S. Pat. No. 3,537,683 to Snell describes a valve seat for use within a butterfly valve and also the method for making the valve seat.
U.S. Pat. No. 3,680,833 to McNeely, Jr. describes a butterfly-type valve having a pair of symetrically disposed veins with peripheral edges that lie in a non-coincident plain.
U.S. Pat. No. 4,079,746 to Killian describes a valve assembly for securing between two flange fittings and an adapter to be used with a valve body having no bolt-receiving holes therein. U.S. Pat. No. 4,275,867 to Schils discloses a disc type valve having a minimal number of rotating parts acting as one integral piece. U.S. Pat. No. 4,399,833 to Holtgraver shows a wafer-type valve for securing between to flange fittings and an adapter device for adapting the valve body to various types of flange fittings in a pipe line. U.S. Pat. No. 4,413,393 Schils discloses a disc type valve assembly in a method of making the same. U.S. Pat. No. 4,457,490 to Scobie provides an improved seat or seal for a butterfly valve. U.S. Pat. No. 4,570,901 to Holtgraver, shows a positioning assembly for rotatable valve, more particularly, an assembly for rotating and positioning the valve element of a rotatable valve. U.S. Pat. No. 4,685,611 to Scobie shows a butterfly valve having a compound, composite, reinforced seat, with the valve having a one piece body.
My U.S. Pat. No. 4,822,001, provides a butterfly valve for insertion between a pair of spaced flanges and fluid flow passageway particularly a resilient seal for use with the butterfly valves which is constructed configured relative to the butterfly valve to provide positive line contact sealing with the adjoining pipe flanges; the disclosure of U.S. Pat. No. 4,822,001 is hereby incorporated by reference. Furthermore my U.S. Pat. No. 4,699,357 describes a reinforced industrial butterfly valve incorporating resilient seal around the interior peripheral wall of the flow passage providing a positive seal during pressure or vacuum service of the valve, and incorporating bushings around the extending proximate end of the valve stem to prevent ware and improve operation.
There are numerous problems associated with the butterfly valves of the prior art. For example, bolts are used to attach the disc to the valve stem and the bolts have a tendency to cut into the disc or "O"-ring seals around the bolt when tightening thereby allowing leakage. Material can flow through the damaged seals, by the bolts, up and down the shaft, and out of the top of the valve causing product loss or contamination. Furthermore, the bolts that hold the disc to the shaft often back out so that play develops between the disc and the shaft when the shaft has rotational pressure put on it. The loose bolts will eventually shear allowing the shaft to turn in the disc and causing valve failure.
Prior art valves have another problem in that the product can leak around the disc when the valve seat wears around the top and the bottom stem holes. This material flows around the worn valve seat at the top and bottom stem hole and the housing area, and the stem seats causing the stem to seize and the valve to fail.
Furthermore, when removing a valve out of rigid pipeline the installer has to force the resilient valve seat between the flow line pipe flanges. The valve seat, generally having a sealing bead on it, can snag on the flange causing the valve seat to pull out of the housing or peel thereby causing the seat to distort, if not tear, and the valve to leak or fail. Moreover, the prior art seats are designed to fit within a dove tail or keystone area of the valve housing. Under the pressure of use, corresponding angled areas of the resilient seat are often compressed into the dove tail or keystone of the housing causing material to be pressed into the angle areas and captured there. This material retained in the dove tail area can result in product contamination from load to load.